This invention relates to the forming, shaping, control and use of fluids and particles such as for example in agriculture and agricultural related fields. One example is the formulation of agricultural inputs, shaping them into droplets or particles, and the distribution of the droplets or particles over a field. Another example is for the encapsulation of seeds with or without chemicals and biological agents or the encapsulation of chemicals with or without biological agents and distribution of the encapsulated seeds or chemicals or biological materials. Still another is for the suspension of seeds for fluid drilling of seeds with or without chemicals or biological materials.
It is known to shape and spray fluids and suspensions with spraying systems. In some applications, the fluids and suspensions are formed into droplets or aerosols and sprayed by the spraying systems. In other applications, the fluids form particles or capsules about seeds or chemicals.
One use of such spraying systems is to apply agricultural inputs to agricultural fields. Commonly, the spraying systems include vehicles that carry the agricultural inputs and spray equipment that apply the agricultural inputs from the vehicle through fixtures supported by booms on the vehicle. The spray equipment may include pumps for liquid and air for distributing the agricultural inputs.
In one type of prior art spraying system for this use, the vehicles used to spray the agricultural fields carry large volumes of diluted active ingredients because it is difficult to spray low volumes of carrier that could deliver more concentrated forms of the active ingredient. Moreover, the vehicles may be outfitted with a high pressure source of air and/or other fluid and thus may require one or more relatively large pumps to spray the liquid containing the active ingredient because high pressure air and/or liquid pressure is needed to form the desired spray and a large volume of liquid containing the active ingredient. In some such systems, the fixtures or nozzles are relatively high above the target for the spray to permit the pattern of fluid to provide an adequate area of coverage with the spray. Usually the pattern shape is determined by the nozzle and has a limited angle. One reason for diluting the active ingredient is because existing spray equipment used in agriculture cannot spray viscous material with the desired size drops and drop distribution and accurate low volume equipment is not economically available. Typically water is used to dilute the active ingredient because it is: (1) inexpensive; (2) benign to plants and beneficial microorganisms; and (3) widely available.
The prior art spray systems have several disadvantages such as for example: (1) they require vehicles carrying the agricultural inputs to carry heavier than desirable weights of agricultural inputs with the associated water carrier; (2) they require the replenishment of the supply of agricultural inputs carried by the spray vehicles periodically, thus increasing the time and expense of spraying; (3) they cannot be used for the application of some beneficial microorganisms because the microorganisms are killed by the high pressure drop experienced by the microorganisms upon release through the spray nozzles used in the prior art techniques for application of agricultural inputs; (4) the low viscosity agricultural inputs drift when sprayed as small drop sizes; (5) some of the carriers used for dilution, such as water, have high surface tension and form beads on contact rather than spreading such as over a leaf; (6) the low viscosity sprayed drops tend to break up because of low shear resistance, thus forming smaller drops that are subject to increased drift; (7) some of the carriers used for dilution, such as water, have unpredictable mineral content and pH variations; (8) the angle of the pattern of sprayed fluid from the nozzles is limited thus requiring the nozzle to be positioned at a high elevation above the spray target to obtain adequate coverage but the high elevation increases drift; (9) the use of some combinations of active ingredients in conventional carriers in some circumstances causes precipitation of active ingredients (10) the prior art systems cannot effectively spray some particles such as particles that have absorbed active ingredients in them that are to be released at a later time and/or environmental condition or over a timed interval because for example they cannot spray viscous formulations that facilitate suspension of such materials; (11) the angle over which the spray is released for hydraulic nozzles is less flexible in prior art nozzles resulting in target coverage limitations; (12) the conventional high pressure hydraulic atomization nozzles used result in excessive nozzle wear and consequential variations in the distribution rate and frequent changes in nozzles; (13) sprayer vehicle speed is limited by the pressure because higher pressures are required for high rates of application and that results in small droplets that drift and there are pressure limitations on the system components; and (14) some of the materials used for carriers are low density and/or evaporate quickly thus increasing the tendency to drift. Moreover, in some instances, the drops lose some carrier by evaporation and the drops end up with concentrations of materials that cause necrosis of plants that are not intended to be adversely affected by the spray.
The prior art attempts to reduce drift have been faced by a dilemma—small drop sizes increase drift problems but provide good coverage of the target and large drop sizes reduce drift but provide poor coverage of the target. The higher concentration sprays have an increased tendency to cause necrosis of plants. For example, some compositions of glyphosate sprays concentrate on plants immune to the effects of glyphosate (Round-up Ready crops are engineered to resist the toxic effects of glyphosate. Round-Up Ready is a trademark of Monsanto Company.) The prior art attempts to resolve this dilemma by compromising between drop size and drift and selecting special nozzles. The special nozzles rely upon air injection into the liquid to facilitate atomization and assist in reducing liquid pressure or the use of liquid pulse modulation systems. These prior art approaches have disadvantages of still providing coverage less effective than desired or longer drift distances than desired and are limited in the application rate adjustments that can be practically achieved as application vehicles change speed in order to maintain constant per unit of field area application rates.
Spray apparatuses are known for spraying viscous materials. The known types of spraying apparatuses have not generally been adapted for use in spraying agricultural inputs nor for conditioning soil or treating microorganisms. Moreover, the known spraying apparatuses for spraying viscous materials are not readily adjustable for adjusting drop size, density or pattern of the drops in the field in accordance with circumstances such as wind speed, distance of spray fixture from the spray target, or speed of a ground vehicle or airplane.
Higher density materials have been available to use as carriers for active ingredients but have not been used because of economic reasons or undesirable characteristics or the belief that such materials would be difficult to spray because of their viscosity or density or because of the custom of using water as the primary carrier material. Many of the active ingredients are difficult to spray with prior art stand alone nozzles or air assist nozzles because they principally require pressure against an orifice to meter and atomize the materials and that cannot be reasonably accomplished with viscous liquids. The long established and reasonable practice has been to dilute the high viscosity active ingredients with low viscosity mobile carriers such as water. However, it has been found that this general prior art approach is not the best approach and has the disadvantage of resulting in a low concentration, higher weight and higher volume load carried by the spray vehicle than is desirable.
It has been proposed in Hopp, et al., Laboratory Studies on Glycerin as a Supplement in Water Soluble Herbicidal Sprays, American Journal of Botany, v. 33, n. 7, (July 1946) pp. 598-600, to add glycerin to herbicidal sprays to aid in uptake of the herbicide by plants. However, the addition of glycerin to sprays has not been adopted, possibly because of the expense and the difficulty of spraying higher viscosity materials.
It is known from U.S. Pat. Nos. 5,520,331; 6,598,802 B2; and 6,241,164 B1 to form bubbles and to burst the bubbles to form a chemical mist for fire suppression. It is suggested that the disclosed apparatus could be used for other applications requiring a chemical mist including the application of chemicals to plant life.
The apparatuses and process disclosed in these patents have a disadvantage in that they are not adapted for use with viscous materials nor adapted to adjust drop size and distribution in a manner suitable for the application of many agricultural inputs.
It is known from U.S. Pat. No. 5,680,993 and Canadian patent CA 2223444 to form drops of agricultural inputs at low pressures by pumping a stream of agricultural input from the center of a stream of air in the same direction as the flow of air. Other jets of air are directed at the stream of agricultural inputs from the side. This prior art device has the disadvantage of requiring the agricultural input to be pumped through a narrow conduit under pressure into the stream of air and thus is limited in handling viscous agricultural products, semisolids and mixtures of semisolids and particles.
It is known to mix fluids and particles and to chemically or physically interact them. Some coating processes, for example, physically interact materials to encapsulate one within the other and some chemical processes such as combustion within an internal combustion engine mix fuel and other gases such as air and at times water and than chemically combine the fuel with oxygen from the air and physically interact the fuel, air and products of combustion with the water if water is present to create mechanical motion. There are many such procedures that shape, mix and interact different fluid materials for useful purposes.
The prior art processes for mixing fluids and particles and chemically or physically interacting them have some common disadvantages. For example, the size of particles or drops or phase of the materials being mixed may not be as appropriate as possible, the selection of materials or proportion of different materials to be interacted may lack some materials or include too many materials or not have a sufficient quantity of some materials or the timing of the interacting of materials may not be suitable or the material compatibility may be for example time or concentration sensitive.
Fluid drilling systems that supply a mixture of gel and seeds onto an agricultural field are known. One prior art fluid drilling apparatus uses impeller pumps or peristaltic pumps or the like to extrude a mixture of gel and seeds. The seeds are germinated prior to planting. Such processes are shown in United Kingdom patent 1,045,732 and in U.S. Pat. No. 4,224,882. These apparatuses have a tendency to distribute seeds with irregular and poorly controlled spacing between the seeds and under some circumstances damage seeds. Moreover, they are prone to plugging from the accumulation of seeds in tubes used in the apparatus.
It is known that an internal delivery tube diameter to seed diameter ratio of at least 3 to 1 is desirable for delivering gel seed mixtures to a planter row. Moreover, when moving fluid gel seed mixtures in a tube, the seeds are propelled much faster at the center line of the tube than at the side walls as a function of the laminar flow conditions which exist for gels having a viscosity that suspends seeds. Because the tube-seed ratio must be so large, adequate flow for fluid drilling of large seeds requires inordinate amounts of fluid and very large pumps to get the seeds delivered. The requirements for pump size and fluid amounts increase exponentially as seed diameter increases linearly for the systems currently in use.
It has also been shown with peristaltic pump systems at seed densities in gel where the volume of gel to volume of seed ratio is less than about four, frequent blocking of the pump inlet port by seeds is experienced. The same limitations apply to piston or air displacement systems. Gels continue to extrude while the seeds pile up at the port as the amount of seed in the mixture increases.
These disadvantages limit the flexibility of the current fluid drilling hardware for delivering large seeds, for using smaller quantities of gel to reduce gel cost per acre and for reducing the volume of gel that must be carried by the planting equipment. Further, this ratio limitation impacts the use of optimal concentrations of treatment chemicals or microorganisms in gels while still being able to use low total amounts of treatment per acre through using for example, gel to seed ratios of 1 to 1. Thus the physics of dispensing seeds suspended in non-Newtonian fluids imposes strict limitations on the utility of the current commercial fluid drilling hardware. Attempts to reduce this problem have relied in some circumstances on seed detectors, and counters or timers that attempt to control the rate of dispensing of seeds in accordance with the rate of travel of a tractor. Such an approach is disclosed in U.S. Pat. No. 3,855,953. This approach has not entirely solved the problem in a satisfactory manner.
It is also known to use screw type mechanisms that receive and capture seeds carried along by a fluid such as air or water and emit the seeds one by one. Such an apparatus is disclosed in U.S. Pat. No. 2,737,314 to Anderson. This apparatus has a disadvantage of damaging seeds and being relatively complicated and unreliable. Augers are known for conveying matter from place to place but such augers have not been successfully adapted up to now to fluid drilling apparatuses. Some such augers have utilized a stream of air at an angle to the flow of material to break off controlled lengths of the material and such an apparatus is disclosed in U.S. Pat. No. 3,846,529. However, this patent does not disclose any method of fluid drilling. The augers used in the prior art are not designed in a manner adequate to separate seeds, to avoid plugging of the conduits carrying the seeds and gel to the nozzle from which they are to be expelled into the ground nor to maintain spacing between seeds while moving them along the auger.
It is also known to use openers and planting shoes to prepare a furrow in which to deposit seeds. The prior art planting shoes have a disadvantage when used for fluid drilling in that there is insufficient space to permit accurate deposit of gel and seeds at a location protected by the shoe. In some prior art planters, additives such as growth stimulants, fungicides, herbicides and/or beneficial microorganisms are deposited separately from the seeds or coated onto the seeds or deposited in carrier materials. The prior art apparatus for applying additives generally deposit granules. These apparatuses have a disadvantage in that they waste expensive additives by applying them nonuniformly and at locations where they are not needed. Attempts to inoculate seeds with beneficial microorganisms other than Rhizobia have not been as successful as desired.